Fluorine-Functionalized Polyphosphazene Immunoadjuvant: Synthesis, Solution Behavior and In Vivo Potency

The inclusion of fluorine motifs in drugs and drug delivery systems is an established tool for modulating their biological potency. Fluorination can improve drug specificity or boost the vehicle's ability to cross cellular membranes. However, the approach has yet to be applied to vaccine adjuvants. Herein, the synthesis of fluorinated bioisostere of a clinical stage immunoadjuvant-poly[di(carboxylatophenoxy)phosphazene], PCPP-is reported. The structure of water-soluble fluoropolymer-PCPP-F, which contains two fluorine atoms per repeat unit-was confirmed using ¹H, ³¹P and ¹⁹F NMR, and its molecular mass and molecular dimensions were determined using size-exclusion chromatography and dynamic light scattering. Insertion of fluorine atoms in the polymer side group resulted in an improved solubility in acidic solutions and faster hydrolytic degradation rate, while the ability to self-assemble with an antigenic protein, lysozyme-an important feature of polyphosphazene vaccine adjuvants-was preserved. In vivo assessment of PCPP-F demonstrated its greater ability to induce antibody responses to Hepatitis C virus antigen when compared to its non-fluorinated counterpart. Taken together, the superior immunoadjuvant activity of PCPP-F, along with its improved formulation characteristics, demonstrate advantages of the fluorination approach for the development of this family of macromolecular vaccine adjuvants.

Computational investigation on the effects of pharmaceutical polymers on the structure and dynamics of interleukin2 in heat stress

Application of proteinous drugs can be associated with difficulties during both in storage/transportation and in the body when they are used. However, using pharmaceutical carbohydrates that are widely employed in drug delivery systems, besides the drug can be protected, these systems leading to gradually release the drug over time, or deliver it to the target cell. Using a combination of molecular modeling and simulation techniques, in this study the effects of five carbohydrate polymers of Chitosan, Alginate, Cyclodextrin, Hyaluronic acid and Pectin on structure and dynamics of interleukin2 protein at 298 K and 343 K, are investigated. Data achieved using molecular modeling methods showed that when the temperature rises, the protein stability decreases. Among different polymers, Chitosan and Cyclodextrin have shown to be able to protect protein against the negative effects of high temperatures in comparison with other polymers which suggests that the use of Cyclodextrin biopolymer for the preparation of pharmaceutical formulations of interleukin2 can be the best possible choice among other polymers investigated in this research.Communicated by Ramaswamy H. Sarma.